Formating life-tables to use in survival analysis

I'm trying to use the 'relsurv' package in R to compare the survival of a cohort to national life tables. The code below shows my problem using the example from relsurv but changing the life-table data. I've just used two years and two ages in the life-table data below, the actual data is much larger but gives the same error. The error is 'invalid ratetable argument' but I've formatted it as per the example life-tables 'slopop' and 'survexp.us'.